Wireless communication systems, such as UTRAN (universal mobile telecommunications systems (UMTS) terrestrial radio access network) and code divisional multiple access (CDMA) 2000, provide full duplex communications, where the transmitter and receiver of a wireless communication device may be active at the same time. Typically, duplex communication systems utilize a pair of separate dedicated frequency bands for transmitting and receiving signals. Additionally, a wireless communication device transmitting and receiving signals utilizing multiple pairs of frequency includes a separate transmitting branch and receiving branch for each pair of frequency bands utilized.
In many instances, noise in a particular receive band is generated by transmission signals. Each transmitting branch may include a duplex filter to filter the noise from the transmission signals in the receive band. In a particular example, a tri-band wireless communication device includes three duplex filters that each filter noise caused by transmission signals of a respective transmitting band from a corresponding receive band. Further, carrier signals transmitted from an antenna of a wireless communication device in a particular band can jam a receiver device of a transceiver due to the strength of the carrier signal. Consequently, each receiving branch includes a filter to decrease the strength of the transmitted signal and reduce the effect of the transmitted signal on the receiver device.
In addition, to the filtering components in the transmitting branch and receiving branch for each pair of frequency bands, a wireless communication device may include additional components for each band. For example, each transmitting branch of a wireless communication device may include a power amplifier and a high-pass filter and each receiving branch may include a low noise amplifier. Further, the transceiver of a wireless communication device may include further components for each band utilized by the wireless communication device, such as a power amplifier for each transmitting branch and a low noise amplifier for each receiving branch. The transceiver may also include additional mixing circuitry for the transmitting and receiving branches based on the number of power amplifiers and low noise amplifiers included in the transceiver. A switch is also utilized to direct signals of each band of a wireless communication device to the proper transmitting branch or receiving branch. Therefore, as the number of bands utilized by a wireless communication device increases, the number of components of the wireless communication device also increases. An increased number of components results in a higher cost of the wireless communication device, increased size, and increased power consumption to achieve sufficient power output.